RasGRF proteins: implication in photoreceptor´s nuclear movement
Speaker: David Jimeno
Centro de Investigación del Cáncer (CIC-IBMCC), lab 1
Salón de Actos del CIC
RasGRF1 and RasGRF2 are members of a guanine exchange factor (GEF) family of proteins capable of activate Ras and Rho GTPases, participating in the signal transduction from the external stimuli to the interior of the cell. They are expressed predominantly in the central nervous system (CNS) where they are involved in different processes.
Studies carried out in the RasGRF1 knockout mice revealed important functions for this protein in the visual system. These mice have an impaired retinal function evident in the electroretinogram (Fernandez-Medarde y cols. 2009). The transcriptional analysis showed an elevated number of genes whose expression is altered in the retinas of these animals, among them, several genes where mutations have been described to cause different retinal pathologies. Despite of that, until now, no morphologic alterations have been described in the retinas of these animals. Using immunohistochemistry techniques we have detected alterations in the nuclear positioning in cones, one of the two types of photoreceptors present in the retina. In the seminar I will describe the spatial and temporal distribution of these alterations, the involvement of each of the RasGRF proteins in this phenotype and the proteins and signaling pathways that may be affected by the lack of RasGRF in relation to the nuclear movement.